Hank.. if you have a link to that article talking about the chevy rockers id like to take a gander at it.. if you wouldnt mind.. sounds really interesting!

 

Since we are back to Monday
and business hours
either:

Larry Shepard at Mopar Performance
Jim Szilagyi at Dodge Motorsports Engineering
someone at Shady Dell Speed Shop
someone at KRC Performance
someone at Hughes Engine
someone at Jessel
someone at Harlan Sharp

could easily answer the question of whether
1992-2003 factory Magnum rocker arms can be replaced
with (year?) of Viper V10 factory rocker arms

It seems proven that the Viper V10 rocker arms will bolt in place and let the engine run.

The questions are:

Do the tip pads of the Viper V10 rocker arms correctly line up with the 3.9/5.2/5.9 valve stem centers?

If the tip of the Viper V10 rocker rams sticks out too far and does not line up with the 3.9/5.2/5.9 valve stem center...then the ratio will be less than 1.7
What is the 'true ratio' when these V10 rockers are bolted on?

 

for shott8283,

Steve Dulcich's articles on the Magnum V8s are not all on line,
but these are:

http://www.popularhotrodding.com/tec..._engine_specs/

in the above article, note the quote:

"The valvetrain arrangement departs from the production Magnum theme, as the heads are fitted with 3/8-inch studs and guide plates to accept common small-block Chevy rocker arms. This may seem strange, but actually the spacing in the stock Magnum makes the valvetrain interchangeable with Chevy rockers. Stock Magnums are converted to aftermarket Chevy rockers by removing the stock paired pedestals and rocker attachment bolts and substituting studs and guide plates. The complication in OE heads is that the heads are tapped for 5/16-inch fasteners, rather than the 3/8-inch specifications required for typical aftermarket studs. Special studs with reduced thread diameters to match the heads are used for this conversion."

Dulcich's other articles on the Magnums are well worth reading:

DIY porting of the Magnum cylinder head:

http://www.popularhotrodding.com/eng...ylinder_heads/

a Magnum 318 combination

http://www.carcraft.com/howto/116_0401_318/index.html

 

The distance on the Head between the valve and the center bolt in the rocker arm is not going to change. So there is no way to increase the ratio by installing one with a longer tip rocker arm. The distance between the pushrod and the center bolt on the rocker is where you gain the ratio. If I can find the old ones from my truck and an extra viper one I have I will post a picture of the difference.

 

Yes, that is the key point
we want to know the precision distance
from the centerline of the valve stem
to the centerline of the mounting stud
on the 3.9/5.2/5.9 V8s
as compared to
the V10

However, North Carolina engine shops routinely change valvetrain geometry.
If you want to go to a custom rocker arm
the stud mount tapped hole
can be offset drilled fore or aft of the original spot and retapped larger.

The near-geniuses at Harlan Sharps and Jessel have devised bedplates for almost any cylinder head in order to mount superior & expensive valvetrain components.

When Duke U engineering students were touring the Hendrick Motorsports shops in 1995 one of them spoted a chevy small block cylinder head lying on the floor that had a different valvespring/rocker/pushrod combination on each of the four cylinders on that head, including a Formula One style airspring. When the student asked about it, our tour guide quickly reached down and set a crate overtop of it and said: "You weren't supposed to see that"

 

If you install a rocker with a longer fulcrum to tip distance it will change the ratio. If the rocker tip rides between the center of the valve stem to the outer edge or between the inner edge to center, the ratio will be different than if it rides properly across the center.

Not only will this type of incorrect geometry play hell on your valve tips as HankL mentioned, but it will also eventually wearyour valve guides out of round. I read somewhere about an older engine builder whose sight was going south that checks the rocker tip to valve stem geometry by coloring the tip of the stem with a Sharpie. He then installs the rocker and hand cranks the motor several revolutions by hand. The rocker tip rubs the ink off where it rides across the stem.

 

I have a Fastman and will attest that performance gains are noticable and it was money well spent. So, phooey on you. Back up what you say with facts and not some diatribe of random diarrhea. [sm=boosign.gif][sm=forgetit.gif]

 

Does this mean the HS are good?

 

What does a Fastman have to do with Viper rockers?

 

Read the original post I quoted for my response. [:@]